US voters support increased use of renewable power but would pay only about $10 per month extra for it, according to an opinion poll that highlights the difficulties facing many forms of lower-carbon energy. The poll also identifies reduced US dependence on foreign oil as a top priority for energy policy and shows support for greater use of natural gas, in spite of concerns about possible pollution caused by shale gas production. The results suggest that higher-cost forms of alternative energy - such as offshore wind, some types of solar power, new nuclear reactors and emissions-free